Uncommon forms for chemical names have been retained where they occur in the text, e.g. "atropin" for "atropine"; "asparagin" for "asparagine", etc. The spellings of "Sidot blend" and "Sidot blende" are used interchangeably. "PH" or P_{H} (subscript H) is used throughout for the scale of alkali-acidity where the modern usage is "pH". On page 173, the citation for NUTTING, P. G.: 1908 has page range pp. 261-039. This is as it appears in the original, but is probably in error. Minor corrections to formatting and missing punctuation (mostly in the bibliography) have been regularised without an explicit note. Where changes to the text have been made in the case of spelling or type-setting errors, these are listed as follows: Page ix: changed "Phoshorescence" to "Phosphorescence" (II. LUMINESCENCE AND INCANDESCENCE ... Phosphorescence and fluorescence.) Page ix: changed "Biozymoxyluminescence" to "Biozymoöxyluminescence" (V. THE CHEMISTRY OF LIGHT PRODUCTION, PART I ... "Biozymoöxyluminescence.") Page x: changed "chemi-luminescence" to "chemiluminescence" in two instances (Reaction velocity and chemiluminescence. Temperature and chemiluminescence.) Page 4, Table 1: changed period "_Bacillus_." to comma "_Bacillus_," in list(_Bacterium_, _Photobacterium_, _Bacillus_, _Pseudomonas_, ...) Page 5, Table 1: removed comma after "_Cunina_". Page 15: changed "th" to "the" (Less well known is the _Ignis fatuus_) Page 21, Table 2: changed "16" to ".16" (... above 12 km. to .16 cm.) Page 26: re-positioned period outside of parentheses "after being illuminated (_photoluminescence_)." Page 29: changed "platino-cyanide" to "platinocyanide" (Fluorescent screens of barium platinocyanide) Page 29: added missing comma (willemite (Zn_{2}SiO_{4}), Sidot blend) Page 34: added missing closing quotation mark ("It is altogether probable that the cause of this" ...) Page 39: superscript "2" changed to subscript "2" in Na_{2}CO_{3} (the pyrogallol-formaldehyde-Na_{2}CO_{3}-H_{2}O_{2} reaction) Page 41: "50-metre candles" changed to "50 metre-candles" (Below 0.5 and above 50 metre-candles visibility varies ...) Page 42, Table 4: changed "Fraünhofer" to "Fraunhofer" in the caption and table heading (Fraunhofer Lines) Page 47, Table 5: changed "Forster" to "Förster" (Bacteria ... Förster, 1887) Page 56, Fig 12 caption: "Forsythe" changed to "Forsyth" (_after Hyde, Forsyth and Cady_) Page 72: added missing closing parenthesis "the molluscs (_Pholas_ and _Phyllirhoë_)" Page 74: "secretion" changed to "section" (A section of the epithelium shows large mucous-producing cells ...) Page 75: added missing closing punctuation (At least one, probably two, are concerned in light production.) Page 75: changed "intra-cellular" to "intracellular" (animals possessing light cells with intracellular luminescence) Page 81; Fig. 29 caption: added missing comma (_chr.^1_, chromatophore; ...)